I ran into this issue. Here’s the advice that worked for me:
Make sure Apple TV and your TV are active when you begin the integration. You wil receive two PIN requests on the R2 and should get two PINs displayed (one at a time) on your TV.
One more thing: even after doing these things, the integration was not working for me. Only a factory reset cured the problems. Be aware that any logins you’ve entered into the streamer wil be lost, so this step is a last resort